Origin: The pepino dulce is native to the temperate Andean regions of
Colombia, Peru and Chile. The plant is not known in the wild, and the details
of it origin are not known. The fruit is grown commercially in New Zealand,
Chile and Western Australia. The pepino dulce was being grown in San Diego
before 1889 and was listed by Francisco Franceschi of Santa Barbara in 1897.
Improved cultivars were imported into California from New Zealand and
elsewhere in more recent times.

Adaptation: The pepino dulce is a fairly hardy plant that grows at altitudes
ranging from near sea level to 10,000 ft. in its native regions. However it
does best in a warm, relatively frost-free climate. The plant will survive a
low temperature of 27 to 28° F if the freeze is not prolonged, but may loose
many of its leaves. It can be grown in many parts of central and southern
California, although it does best in locations away from the coast and is not
well suited for hot, interior gardens. Pepino dulce has been grown and has
fruited in the milder areas of northern California (Sunset Climate Zones 16
and 17). The plant is small enough to be grown satisfactorily in a container.

DESCRIPTION

Growth Habit: Pepino dulce is a small, unarmed, herbaceous plant or bush
with a woody base and fibrous roots. Growth is erect or ascending to about 3 feet
high and several feet across. It is similar in these respects to a
small tomato vine, and like the tomato may need staking or other support.

Foliage: The bright green leaves are sparsely covered with very small hairs.
In appearance the pepino dulce is much like a potato plant, but the leaves
may take many forms--simple and entire, lobed, or divided into leaflets.

Flowers: The small flowers are blue, violet-purple or white marked with
purple, and are similar in form to unopened potato flowers. The pepino dulce
is deemed to be parthenocarpic but a much heavier crop results from
self-pollination or cross-pollination. The plants will not set fruit until the
night temperatures are above 65° F.

Fruit: The fruit also show considerable diversity in size and shape. In the
areas of its origin there are small oblong types with many seeds, while
others are pear or heart-shaped with few or many seeds. Still others are
round, slightly larger than a baseball and completely seedless. The colors
also vary--completely purple, solid green or green with purple stripes, or
cream colored with or without purple stripes. The fruit of cultivars grown
in this country are usually round to egg-shaped, about 2 to 4 inches long,
with some growing up to 6 inches. The skin is typically yellow or purplish
green, often with numerous darker streaks or stripes. The flesh is greenish
to white and yellowish-orange. Better quality fruit is moderately sweet,
refreshing and juicy with a taste and aroma similar to a combination of
cantaloupe and honeydew melon. In poor varieties there can be an unpleasant
"soapy" aftertaste. The fruit matures 30 to 80 days after pollination.

CULTURE

Location: The plant likes a sunny or semi-shaded, frost-free location,
sheltered from strong winds. It does well planted next to a south-facing wall
or in a patio.

Soil: The pepino dulce does best in a fertile (but not too fertile), free
draining, neutral soil ( pH of 6.5-7.5). It is not as tolerant of salinity
as the tomato. Mulching will help suppress weed growth.

Irrigation: The pepino dulce is quite sensitive to moisture stress as their
root systems spread out and are quite shallow. Irrigation techniques are thus
crucial for the health of the plants as well as for pollination, fruit set
and quality of the fruit crop. Some growers feel that overhead sprinkling may
even favor increased pollination. Microjets appear to deliver moisture
better than trickle irrigation.

Fertilization: The plants should be fertilized in a manner similar to a
tomato plant, mixing in some well-rotted manure to the plant site several
weeks in advance and supplementing with a 5-10-10 NPK granular fertilizer as
needed. Soils that are too rich produce vigorous vegetative growth which can
lead to reduced fruit set and quality, plus an increase in pest problems.

Pruning: Pruning of the pepino dulce is not needed unless the plant is being
trained to a trellis. In this case treat it as one would a tomato vine.
Opening the the fruits to light increases the purple striping and improves
the general appearance.

Frost Protection: In areas where frost may be a problem, providing the
plant with some overhead protection or planting them next to a wall or a
building may be sufficient protection. Individual plants are small enough to
be fairly easily covered during cold snaps by placing plastic sheeting, etc.
over a frame around them. Plastic row covers will also provide some frost
protection for larger plantings. Potted specimens can be moved to a
frost-secure area.

Propagation: The pepino dulce can be grown from seeds, but is usually
propagated vegetatively from cuttings. Three to five inch stem cuttings are
taken leaving 4 or 5 leaves at the upper end. Treatment with rooting hormones
will help increase uniformity in rooting and development of heavier root
systems. The cuttings are then placed in a fast-draining medium and placed
under mist or otherwise protected from excessive water loss. Bottom heat also
is helpful. With the right conditions most of the cuttings quickly root and
are ready for potting up in individual containers. Rooted cuttings set out
after the danger of frost (February to April) should be large enough to start
blooming shortly after planting. The fruit will then have time to grow and
ripen during the warm summer months. When planted out, a spacing of about
2 to 3 ft. between bushes is recommended.

Pests and Diseases: The plant is affected by many of the diseases and pests
that afflict tomatoes and other solanaceous plants, including bacterial spot,
anthracnose, and blights caused by Alternaria spp. and Phytophthora spp. The
various pests include spider mite, cut worm, hornworm, leaf miner, flea
beetle, Colorado potato beetle and others. Fruit fly is a serious pest where
they are a problem. Greenhouse grown plants are particularly prone to attack
by spider mites, white flies and aphids

Harvest: Individual fruits should not be picked until they are completely
mature to assure the highest flavor and sugar content. Different cultivars
vary, but the ground color of many mature fruits is somewhat yellow to light
orange. Ripe fruit also bruises easily and requires careful handling. Such
fruit should store well for 3 to 4 weeks at around 38° F under relatively
high humidity. Fruit destined for distant markets would need to be picked
earlier just before full ripeness. As it turns out this happens to be a good
time to pick the fruit. Studies have shown that fruit in the middle degree of
ripeness has the best performance in cold storage. Over-ripe fruit suffers
most from physiological problems such as internal breakdown, discoloration
and dehydration. If harvested too early, insufficient ripening and
development of flavor and sweetness can result. The pepino dulce is commonly
chilled and eaten fresh much like a cantaloupe or other melon.

Commercial Potential: The pepino dulce is a successful commercial crop in
several countries such as New Zealand and Chile, and there appears to be no
reason it can't find a niche in this country in Farmer's Market sales and
elsewhere. The fruit is strikingly attractive and its storage capability and
shelf life permit great flexibility in marketing. For good market acceptance
it is important to select cultivars with the sweetest and most flavorful
fruit. Additional breeding and selection is also needed to further enhance
these qualities.

CULTIVARS

Colossal

Very large fruit, mostly cream-colored with light markings of
purple. Very juicy and sweet, free of soapiness, of good melon-like flavor,
especially when vine ripened. Self-fertile, but yields larger fruit when
cross-pollinated.

Ecuadorian Gold

A market cultivar in South America that produces good crops
of pear-like fruits over a long growing season. The fruit has an attractive
color, is well-marked and holds well on the plant. Self-fertile, but should
be thinned for better fruit size.

El Camino

Released in New Zealand in 1982 from material collected in Chile.
Medium to large, egg-shaped fruit with regular purple stripes. Sometimes
produces off-flavored fruits identifiable by their brownish-green color. One
of two leading commercial cultivars in New Zealand.

Miski Prolific

Originated in San Jose, Calif. by Nancy Garrison, as a
seedling of the New Zealand cultivar Miski. Fruit creamy white with a faint
salmon glow, lightly striped with purple. Flesh deep salmon. Flavor rich,
sweet and aromatic, with no soapiness. Seeds few or none. Matures early.
Strong growing plant, bears well without pollination.

Originated in Vista, Calif by Patrick J. Worley. Named after the
city in Ecuador where the original plant was collected. Medium-sized fruit,
strongly striped with purple. Flavor excellent. Vining growth habit, making
an excellent climber or a hanging basket plant. Dark-green leaves with
reddish-purple veins, purple stems. Flowers darker than normal, making an
excellent display.

Temptation

Introduced by the Nurserymen's Association of Western Australia.
Large, high quality fruit.

Toma

Introduced into New Zealand from Chile in 1979, released there in 1983.
Medium-sized, oval fruit, 4 inches long, 3 inches in diameter, apex pointed,
shoulder well rounded. Skin smooth, cream-colored when ripe, prominently
striped with dark purple. Flesh firm, light cream in color, very juicy.
Flavor sweet and refreshing, with ho hint of soapiness. Seeds usually
present. Keeping quality excellent. An important export cultivar in Chile.

Vista

Originated in Vista, Calif. by Patrick J. Worley. A cross of Rio Bamba
and a seedling from South America. Medium-sized fruits have good flavor and
aroma. Upright, fairly compact plant of great vigor, self-fertile and heavy
yielding. Bright green, 3 inch long leaves.

FURTHER READING

Butterfield, Harry M. A History of Subtropical Fruits and Nuts in California.
University of California, Agricultural Experiment Station. 1963.